Method and apparatus for transmitting data

ABSTRACT

Embodiments of the present invention disclose a method and an apparatus for transmitting data, and the method includes: first setting at least two second resource groups in each first resource group of at least one first resource group, and setting at least two reference signals in each of the second resource groups; then encoding data to be transmitted and generating two data streams from the encoded data; then, mapping the two data streams onto an available resource element of two different antenna ports, in which the reference signals corresponding to the two different antenna ports are set on two different second resource groups; and finally, transmitting, on the available resource element of the two different antenna ports, data on the two antenna ports. The present invention is applicable to the field of communications systems.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/066,578, filed on Mar. 10, 2016, which is a continuation of U.S.patent application Ser. No. 14/336,747, filed on Jul. 21, 2014, now U.S.Pat. No. 9,306,652, which is a continuation of International ApplicationNo. PCT/CN2013/070767, filed on Jan. 21, 2013, which claims prioritiesto Chinese Patent Application No. 201210019841.8, filed on Jan. 21, 2012and Chinese Patent Application No. 201210264189.6, filed on Jul. 28,2012, The afore-mentioned patent applications are hereby incorporated byreference in their entireties.

TECHNICAL FIELD

The present invention relates to the field of communications systems,and in particular, to a method and an apparatus for transmitting data.

BACKGROUND

A long term evolution (LTE, Long Term Evolution) standard Rel-8/9/10communications system improves system performance by adopting a dynamicscheduling technology, that is, a base station (eNB, evolved Node B)schedules and allocates resources according to a channel situation of auser equipment, so that a scheduled user performs transmission on anoptimal channel of the user equipment

However, the problem of a limited capacity of a PDCCH (Physical DownlinkControl Channel, physical downlink control channel) is much highlightedin further evolution of an LTE Rel-10 system. The multi-user MIMO(Multiple-Input Multiple-Output, multiple-input multiple-output) isincreasingly applied in an evolution system to improve the spectralefficiency of the system, which increases the number of user equipmentsscheduled simultaneously, and therefore more PDCCHs are required. Basedon this, an existing PDCCH is enhanced, that is, a part of resources aredivided from an original PDSCH area to transmit an enhanced PDCCH(e-PDCCH, Enhanced Physical Downlink Control Channel, enhanced physicaldownlink control channel). In this way, the resources allocated to thee-PDCCH are greatly flexible and are not limited to three OFDM(Orthogonal Frequency Division Multiplexing, orthogonal frequencydivision multiplexing) symbols anymore, thereby improving the capacityof the PDCCH or the number of user equipments scheduled simultaneously;meanwhile, the e-PDCCH may also adopt a DMRS (UE-specific ReferenceSignal, demodulation reference signal) based transmission manner and mayimplement spatial reuse to improve the transmission efficiency of thecontrol channel.

Currently, when data is transmitted in a DMRS based transmittingdiversity manner, after space time block code (Alamouti) coding isperformed separately on two consecutive REs (Resource Element, resourceelement) on a frequency domain and two consecutive REs on a time domain,the data is transmitted in two manners, namely, SFBC (Space FrequencyBlock Coding, space frequency block coding) and STBC (Space Time BlockCoding, space time block coding), simultaneously. However, because dataof an e-PDCCH is transmitted by adopting two transmitting diversitysolutions, the complexity of transmitting and receiving on the eNB andthe UE (User Equipment, user equipment) is increased.

SUMMARY

Embodiments of the present invention provide a method and an apparatusfor transmitting data, so as to solve the problem of an increase incomplexity of transmitting and receiving on an eNB and a UE (UserEquipment) due to two transmitting diversity solutions that are adoptedwhen data is transmitted in a DMRS based transmitting diversity manner.

The embodiments of the present invention adopt the following technicalsolutions:

A method for transmitting data includes:

setting at least two second resource groups in each first resource groupof at least one first resource group, in which each of the secondresource groups is capable of bearing at least two reference signals,and each reference signal of the at least two reference signals iscorresponding to a different antenna port;

encoding data to be transmitted and generating two data streams from theencoded data;

mapping the two data streams onto an available resource element of twodifferent antenna ports, in which the reference signals corresponding tothe two different antenna ports are borne on two different secondresource groups of the first resource group; and transmitting, on theavailable resource element of the two different antenna ports, data onthe two antenna ports.

An apparatus for transmitting data includes:

a setting unit, configured to set at least two second resource groups ineach first resource group of at least one first resource group, in whicheach of the second resource groups is capable of bearing at least tworeference signals, and each reference signal of the at least tworeference signals is corresponding to a different antenna port;

a generating unit, configured to encode data to be transmitted andgenerate two data streams from the encoded data;

a mapping unit, configured to map the two data streams generated by thegenerating unit onto an available resource element of two differentantenna ports, in which the reference signals corresponding to the twodifferent antenna ports are borne on two different second resourcegroups of the first resource group, and the two different secondresource groups are set by the setting unit; and

a transmitting unit, configured to transmit, on the available resourceelement of the two different antenna ports, data mapped by the mappingunit onto the two antenna ports.

In the method and the apparatus for transmitting data provided by theembodiments of the present invention, first at least two second resourcegroups are set in each first resource group of at least one firstresource group, and at least two reference signals are set in each ofthe second resource groups; then two data streams are generated afterdata required to be transmitted is coded; then, the two data streams aremapped onto available resource element of two different antenna ports,in which reference signals corresponding to the two different antennaports are set on two different second resource groups; and finally, dataon the two antenna ports is transmitted on the available resourceelement of the two different antenna ports. Currently, data can betransmitted in two manners, namely, SFBC and STBC, simultaneously, butbecause data transmission of an e-PDCCH needs to adopt two transmittingdiversity solutions, complexity of transmitting and receiving on an eNBand a UE is increased. However, in the embodiments of the presentinvention, data can be transmitted only in need of one transmittingdiversity solution, so as to solve the problem of the increase in thecomplexity of transmitting and receiving on the eNB and the UE.

BRIEF DESCRIPTION OF THE DRAWINGS

To illustrate the technical solutions in the embodiments of the presentinvention more clearly, the following briefly introduces theaccompanying drawings required for describing the embodiments or theprior art. Apparently, the accompanying drawings in the followingdescription show merely some embodiments of the present invention, andpersons of ordinary skill in the art may still derive other drawingsfrom these accompanying drawings without creative efforts.

FIG. 1 is a flow chart of a method for transmitting data according toEmbodiment 1 of the present invention;

FIG. 2 is a schematic structural diagram of an apparatus fortransmitting data according to Embodiment 1 of the present invention;

FIG. 3 is a flow chart of a method for transmitting data according toEmbodiment 2 of the present invention;

FIG. 4 is a schematic structural diagram of an apparatus fortransmitting data according to Embodiment 2 of the present invention;

FIG. 5 is a schematic diagram of a physical resource block pair of DMRSport 7;

FIG. 6 is a schematic diagram of a physical resource block pair of DMRSport 8;

FIG. 7 is a schematic diagram of a physical resource block pair of DMRSport 9;

FIG. 8 is a schematic diagram of a physical resource block pair of DMRSport 10;

FIG. 9 is a schematic diagram of coding of a physical resource blockpair of DMRS port 7;

FIG. 10 is a schematic diagram of coding of a physical resource blockpair of DMRS port 8;

FIG. 11 is a schematic diagram of coding of a physical resource blockpair of DMRS port 9;

FIG. 12 is a schematic diagram of coding of a physical resource blockpair of DMRS port 10; and

FIG. 13 is a schematic diagram of interference between different RRHs.

DETAILED DESCRIPTION

The following clearly describes the technical solutions in theembodiments of the present invention with reference to the accompanyingdrawings in the embodiments of the present invention. Apparently, thedescribed embodiments are merely a part rather than all of theembodiments of the present invention. All other embodiments obtained bypersons of ordinary skill in the art based on the embodiments of thepresent invention without creative efforts shall fall within theprotection scope of the present invention.

To make the advantages of the technical solutions of the presentinvention more comprehensible, the following describes the presentinvention in further detail with reference to the accompanying drawingsand embodiments.

Embodiment 1

This embodiment provides a method for transmitting data, and as shown inFIG. 1, the method includes the following steps:

101. Set at least two second resource groups in each first resourcegroup of at least one first resource group, in which each of the secondresource groups is capable of bearing at least two reference signals,and each reference signal of the at least two reference signals iscorresponding to a different antenna port.

The first resource group may be a physical resource block pair, thesecond resource group may be a resource element RE, and each referencesignal of the at least two reference signals corresponds to one antennaport; the second resource groups are orthogonal to each other in timeand frequency, and each of the second resource groups includes 12 REs.

For example, eight antenna ports are defined as DMRS port 7 to DMRS port14, each DMRS port corresponds to a DMRS, and information about eachDMRS includes a time frequency resource occupied by the DMRS and a DMRSsequence. DMRSs associated with the DMRS ports {7, 8, 11, 13} aredefined or set on 12 REs on a physical resource block pair (PRB pair).Specifically, a physical resource block contains 12 consecutivesubcarriers on a frequency domain and 7 consecutive OFDM symbols on atime domain, and a physical resource block pair refers to twoconsecutive physical resource blocks in the time. For example, aphysical resource block pair contains 12 consecutive subcarriers on thefrequency domain and 14 consecutive OFDM symbols on the time domain, inwhich the former 7 OFDM symbols belong to a first physical resourceblock, and the latter 7 OFDM symbols belong to a second physicalresource block. DMRSs associated with the DMRS ports {9, 10, 12, 14} aredefined or set on the other 12 REs on the same PRB pair. FIG. 5 to FIG.8 separately denote situations of time frequency resources occupied byfour DMRS ports {7, 8} and {9, 10} in a PRB pair, and ports 7 and 8occupy the same time frequency resource but are distinguished using DMRSsequences associated with them; ports 9 and 10 are similar to ports 7and 8. Under a situation in which 8 DMRS ports exist, DMRSs associatedwith the ports {7, 8, 11, 13} occupy the same time frequency resourceand are distinguished using DMRS sequences; likewise, DMRSs associatedwith the ports {9, 10, 12, 14} occupy the same time frequency resourceand are distinguished using DMRS sequences.

102. Encode data to be transmitted and generate two data streams fromthe encoded data.

The coding manner is space frequency block coding or space time blockcoding.

In another aspect, the coding may also be precoding, that is, aprecoding operation is performed on the data required to be transmitted,because the space frequency block coding or the space time block codingcan be denoted as a special implementation manner of precoding. Aspecific operation of precoding is relevant to a reference signal usedat the time of transmitting data. When the used reference signal is acell-specific reference signal, such as a CRS (cell-specific referencesignal) in an LTE system, a precoding operation at this time is toprecode data using a precoding matrix or vector, and then each datastream after the precoding corresponds to an antenna port correspondingto a CRS; when the used reference signal is a user-equipment-specificreference signal, such as a DMRS (UE-specific reference signal) in anLTE system, a precoding operation at this time is that data directlycorresponds to an antenna port corresponding to a DMRS to obtain acorresponding data stream. For example, a precoding operation

${\begin{bmatrix}{y^{(7)}\lbrack i\rbrack} \\{y^{(8)}\lbrack i\rbrack}\end{bmatrix} = \begin{bmatrix}{x^{(0)}(i)} \\{x^{(1)}(i)}\end{bmatrix}},$

i=0, 1, Λ, N−1, N is an integer denotes that data x⁽⁰⁾(i) directlycorresponds to DMRS antenna port 7, and data x⁽¹⁾(i) directlycorresponds to DMRS antenna port 8, and obtained corresponding datastreams are y⁽⁷⁾[i], y⁽⁸⁾[i], i=0, 1, Λ, N−1.

Here, a first data stream corresponds to an antenna port correspondingto a reference signal in the first one of the second resource groups inthe first resource group, and a second data stream corresponds to anantenna port corresponding to a reference signal in the second one ofthe second resource groups in the first resource group. The lengths oftwo data streams generated after the data is coded may be equal or mayalso be unequal. For example, the data required to be transmitted isx(0), x(1), κ, x(N−1), N is an even number, and two data streams whoselengths are equal are obtained by performing space frequency blockcoding or space time block coding on the data; two data streams whoselengths are equal can also be obtained by precoding the data, forexample,

${\begin{bmatrix}{y^{(7)}\lbrack i\rbrack} \\{y^{(9)}\lbrack i\rbrack}\end{bmatrix} = \begin{bmatrix}{x(i)} \\{x( {i + {N/2}} )}\end{bmatrix}},$

i=0, 1, Λ, N/2−1; two data streams whose lengths are unequal may also beobtained by precoding the data, for example, a first data stream isy⁽⁷⁾[i]=x(i), i=0, 1, Λ, L−1, L<N, L≠N/2, a second data stream isy⁽⁹⁾[j]=x(j+L), j=0, 1, Λ, N−1−L, and it is assumed here that DMRS portsused in the at least one first resource group are ports 7 and 9.Additionally, the first data stream may includey_(first resource group 1) ⁽⁷⁾[i]=X(i), i=0, 1, Λ, L₁−1, L₁<N andy_(first resource group 2) ⁽⁸⁾[i]=X(i+L₁), i=0, 1, Λ,L₂−1, L₁+L₂<N, andthe second data stream may include y_(first resource group 1)⁽⁹⁾[i]=x(i+L₁+L₂), i=0, 1, Λ,L₃−1, L₁+L₂+L₃<N andy_(first resource group 2) ⁽¹⁰⁾[i]=x(i+L₁+L₂+L₃), i=0, 1, Λ, L₄−1,L₁+L₂+L₃+L₄=N, in which respective values of L₁, L₂, L₃, L₄ may be 0; itis assumed here that two first resource groups exist, DMRS ports used inthe first one of the first resource groups are ports 7 and 9, and DMRSports used in the second one of the first resource groups are ports 8and 10.

103. Map the two data streams onto an available resource element of twodifferent antenna ports.

Respective reference signals corresponding to the two different antennaports are set on two different second resource groups. Additionally, anavailable resource element of each antenna port refers to a resourceelement that can be configured to transmit a data stream generated bythe coding. For example, except a resource element occupied by a PDCCHand a reference signal, another resource element can be configured totransmit the data stream.

104. Transmit, on the available resource element of the two differentantenna ports, data on the two antenna ports.

This embodiment provides an apparatus for transmitting data, and asshown in FIG. 2, the apparatus includes a setting unit 21, a generatingunit 22, a mapping unit 23, and a transmitting unit 24.

The setting unit 21 is configured to set at least two second resourcegroups in each first resource group of at least one first resourcegroup, in which each of the second resource groups is capable of bearingat least two reference signals, and each reference signal of the atleast two reference signals corresponds to a different antenna port.

The first resource group is a physical resource block pair, the secondresource group is a resource element RE, and each reference signal ofthe at least two reference signals is corresponding to one antenna port;the second resource groups are orthogonal to each other in time andfrequency, and each of the second resource groups includes 12 REs.

For example, eight antenna ports are defined as DMRS port 7 to DMRS port14, each DMRS port corresponds to a DMRS, and information about eachDMRS includes a time frequency resource occupied by the DMRS and a DMRSsequence. DMRSs associated with the DMRS ports {7, 8, 11, 13} aredefined or set on 12 REs on a physical resource block pair (PRB pair).Specifically, a physical resource block contains 12 consecutivesubcarriers on a frequency domain and 7 consecutive OFDM symbols on atime domain, and a physical resource block pair refers to twoconsecutive physical resource blocks in the time. For example, aphysical resource block pair contains 12 consecutive subcarriers on thefrequency domain and 14 consecutive OFDM symbols on the time domain, inwhich the former 7 OFDM symbols belong to a first physical resourceblock, and the latter 7 OFDM symbols belong to a second physicalresource block. DMRSs associated with the DMRS ports {9, 10, 12, 14} aredefined or set on the other 12 REs on the same PRB pair. FIG. 5 to FIG.8 separately denote situations of time frequency resources occupied byfour DMRS ports {7, 8} and {9, 10} in a PRB pair, and ports 7 and 8occupy the same time frequency resource but are distinguished using DMRSsequences associated with them; ports 9 and 10 are similar to ports 7and 8. Under a situation in which 8 DMRS ports exist, DMRSs associatedwith the ports {7, 8, 11, 13} occupy the same time frequency resourceand are distinguished using DMRS sequences; likewise, DMRSs associatedwith the ports {9, 10, 12, 14} occupy the same time frequency resourceand are distinguished using DMRS sequences.

The generating unit 22 is configured to encode data to be transmittedand generate two data streams from the encoded data.

The coding manner is space frequency block coding or space time blockcoding.

Additionally, the coding may also be precoding, that is, a precodingoperation is performed on the data required to be transmitted, becausethe space frequency block coding or the space time block coding can bedenoted as a special implementation manner of precoding.

The mapping unit 23 is configured to map the two data streams generatedby the generating unit 22 onto an available resource element of twodifferent antenna ports.

Respective reference signals corresponding to the two different antennaports are set on two different second resource groups. Additionally, anavailable resource element of each antenna port refers to a resourceelement that can be configured to transmit a data stream generated bythe coding. For example, except resource element occupied by a PDCCH anda reference signal, another resource element can be configured totransmit the data stream.

The transmitting unit 24 is configured to transmit, on the availableresource element of the two different antenna ports, data mapped by themapping unit 23 onto the two antenna ports.

In the method and the apparatus for transmitting data provided by thisembodiment of the present invention, first at least two second resourcegroups are set in each first resource group of at least one firstresource group, and at least two reference signals are set in each ofthe second resource groups; then two data streams are generated afterdata required to be transmitted is coded; then, the two data streams aremapped onto an available resource element of two different antennaports, in which reference signals corresponding to the two differentantenna ports are set on two different second resource groups; andfinally, data on the two antenna ports is transmitted on the availablean resource element of the two different antenna ports. Currently, datacan be transmitted in two manners, namely, SFBC and STBC,simultaneously, but because data transmission of an e-PDCCH needs toadopt two transmitting diversity solutions, complexity of transmittingand receiving on an eNB and a UE is increased. However, in thisembodiment of the present invention, data can be transmitted only inneed of one transmitting diversity solution, so as to solve the problemof the increase in the complexity of transmitting and receiving on theeNB and the UE and the problem of poor channel estimation performance,and additionally, the time-frequency orthogonal reference signal alsoimproves the channel estimation performance.

Embodiment 2

This embodiment provides a method for transmitting data, and as shown inFIG. 3, the method includes the following steps:

301. Set at least two second resource groups in each first resourcegroup of at least one first resource group, and set at least tworeference signals in each of the second resource groups.

The first resource group is a physical resource block pair, the secondresource group is a resource element RE, and each reference signal ofthe at least two reference signals is corresponding to one antenna port;the second resource groups are orthogonal to each other in time andfrequency, and each of the second resource groups includes 12 REs.

302. Encode data to be transmitted and generate two data streams fromthe encoded data.

The coding manner is space frequency block coding or space time blockcoding.

Additionally, the coding may also be precoding, that is, a precodingoperation is performed on the data required to be transmitted, becausethe space frequency block coding or the space time block coding can bedenoted as a special implementation manner of precoding.

303. Map the two data streams onto an available resource element of twodifferent antenna ports.

Respective reference signals corresponding to the two different antennaports are set on two different second resource groups.

304. Transmit, on the available resource element of the two differentantenna ports, data on the two antenna ports.

Specifically, in this embodiment of the present invention, the antennaports are DMRS ports, and as shown in FIG. 5 to FIG. 8, REs of twosecond resource groups are defined in a first resource group PRB pair,in which each group of resource elements includes 12 REs, and these twogroups of REs are orthogonal in time and frequency; two referencesignals are defined on the first group of 12 REs, these two referencesignals corresponds to DMRS ports 7 and 8, and the other two referencesignals are defined on the second group of 12 REs, and correspond toDMRS ports 9 and 10. The two antenna ports adopted in this embodimentare associated with the reference signals defined on the first group of12 REs and the second group of 12 REs, for example, DMRS ports 7 and 9,DMRS ports 8 and 10, DMRS ports 8 and 9, and DMRS ports 8 and 10.Further, the adopted two ports are DMRS ports 7 and 9, the adoptedtransmitting diversity solution is SFBC, the SFBC codes e-PDCCH datarequired to be transmitted to obtain two data streams, and these twodata streams are separately mapped onto DMRS ports 7 and 9. As shown inFIG. 9 and FIG. 10, in the drawings, the former three columns of REs isa PDCCH area, that is, resource elements of this part are unavailable,“1” and “2” on the same time frequency resource location on the twoports are used to transmit the output of an Alamouti code, and resourceelements marked with “1” and “2” are available resource elements.

For example, an e-PDCCH modulation symbol required to be transmitted isD={d₀,d₁,Λ,d_(2N−1)}, in which d_(i), i=0, 1, . . . , 2N−1 is amodulation symbol, and N is a positive integer. D is divided into twomodulation symbol sets X and Y, which are X={x₀,x₁,Λ,x_(N−1)},Y={y₀,y₁,Λ,y_(N−1)} respectively, in which x_(i)=d_(2i), y_(i)=d_(2i+1),i=0, 1, Λ, N−1; then, SFBC

${{\begin{pmatrix}x_{i} & y_{i} \\{- y_{i}^{*}} & x_{i}^{*}\end{pmatrix}\mspace{14mu} i} = 0},1,\Lambda,{N - 1}$

is performed on element symbols in X, Y, in which * denotes that aconjugation operation is performed to obtain two data streams M and N,which are specifically M={m₀,m₁,Λ,m_(2N−1)} and N={n₀,n₁,Λn_(2N−1)}, inwhich m_(2i)=x_(i), m_(2i+1)=y_(i), n_(2i)=−y_(i)*, n_(2i+1)=x*_(i), andi=0, 1, Λ, N−1; secondly, the two data streams M, N are mapped onto DMRSports 7 and 9 respectively.

The transmitting diversity solution in this embodiment of the presentinvention is not limited to the SFBC. When the number of available OFDMsymbols in a PRB pair is an odd number, as shown in FIG. 11 and FIG. 12,the number of available OFDM symbols is two, and the STBC can also beadopted. In the drawings, the former two columns of REs is a PDCCH area,that is, resource elements of this part are unavailable.

305. When at least two remote radio frequency units are connected to amacro base station and are provided with a cell ID the same as that ofthe macro base station, and one of the at least two remote radiofrequency units provides a service for a user equipment, allocate thedifferent antenna ports to the at least two remote radio frequencyunits, and map data onto the allocated antenna ports to transmit thedata.

Specifically, in a heterogeneous network scenario, besides the macrobase station, a plurality of RRHs is set within the coverage of a macrocell, these RRHs are connected to the macro base station through opticfibers or in other manners, and these RRHs are provided with a cellidentity (ID) the same as that of the macro cell where these RRHs arelocated; because of the DMRS based transmitting mode, each RRH iscapable of individually serving some users, but each RRH is transparentfor the users. Under this scenario, a UE served by a RRH boundary issubject to interference from another neighboring RRH, and as shown inFIG. 13, UE_5 served by RRH2 is subject to interference from RRH1. Theinfluence of this interference on the DMRS interference is serioussomewhat, because the DMRS is used to estimate a channel, and a datachannel is detected by utilizing the estimated channel.

When this embodiment of the present invention is applied to thisscenario, interference between DMRSs can be avoided by allocatingdifferent DMRS ports to different RRHs or UEs. Without loss ofgenerality, illustration is made using a specific example here. Stilltaking RRH1 and RRH2 in FIG. 13 as an example, DMRS ports that can beallocated to RRH1 or a UE served in RH1 are ports 7 and 9 respectively,and DMRS ports that can be allocated to RRH2 or a UE served in RRH2 areports 8 and 10 respectively. In this way, a UE in each RRH only needs toadopt one transmitting diversity solution SFBC during transmitting.Additionally, because DMRS sequences associated with DMRS ports 7 and 8(or 9 and 10) defined on the same group of resource elements areorthogonal or quasi-orthogonal, interference between DMRSs of UEs at twoRRH boundaries can be avoid or reduced, thereby improving channelestimation performance.

In this embodiment of the present invention, the at least two PRB pairsmay be consecutive or discrete on a frequency domain, and preferably bediscrete. It is assumed below that four PRB pairs are used to transmitan e-PDCCH, and these four PRB pairs are discrete on the frequencydomain, and adopt the transmitting diversity solution. When the e-PDCCHis transmitted, each e-PDCCH can be individually mapped onto some REs inthese four PRB pairs, for example, the e-PDCCH of UE1 is divided intofour parts, and these four parts are mapped onto REs on the fourth andfifth OFDM symbols of PRB pairs 1 to 4; or e-PDCCHs of at least two UEsare placed together and interleaved, and then the interleaved data ismapped into the four PRB pairs according to a certain rule.

This embodiment provides an apparatus for transmitting data, and asshown in FIG. 4, the apparatus includes a setting unit 41, a generatingunit 42, a mapping unit 43, a transmitting unit 44, and an allocatingunit 45.

The setting unit 41 is configured to set at least two second resourcegroups in each first resource group of at least one first resourcegroup, and be capable of bearing at least two reference signals in eachof the second resource groups.

The first resource group is a physical resource block pair, the secondresource group is a resource element RE, and each reference signal ofthe at least two reference signals is corresponding to one antenna port;the second resource groups are orthogonal to each other in time andfrequency, and each of the second resource groups includes 12 REs.

The generating unit 42 is configured to encode data to be transmittedand generate two data streams from the encoded data.

The coding manner is space frequency block coding or space time blockcoding.

Additionally, the coding may also be precoding, that is, a precodingoperation is performed on the data required to be transmitted, becausethe space frequency block coding or the space time block coding can bedenoted as a special implementation manner of precoding.

The mapping unit 43 is configured to map the two data streams generatedby the generating unit 42 onto an available resource element of twodifferent antenna ports.

Respective reference signals corresponding to the two different antennaports are borne on two different second resource groups.

The transmitting unit 44 is configured to transmit, on the availableresource element of the two different antenna ports, data mapped by themapping unit 43 onto the two antenna ports.

The allocating unit 45 is configured to, when at least two remote radiofrequency units are connected to a base station, and one of the at leasttwo remote radio frequency units provides a service for a userequipment, allocate the different antenna ports set by the setting unitto the at least two remote radio frequency units, and the mapping unitmaps data onto the antenna ports allocated by the allocating unit totransmit the data.

In the method and the apparatus for transmitting data provided by thisembodiment of the present invention, first at least two second resourcegroups are set in each first resource group of at least one firstresource group, and at least two reference signals are set in each ofthe second resource groups; then two data streams are generated afterdata required to be transmitted is coded; then, the two data streams aremapped onto an available resource element of two different antennaports, in which reference signals corresponding to the two differentantenna ports are set on two different second resource groups; andfinally, data on the two antenna ports is transmitted on the availableresource element of the two different antenna ports. Currently, data canbe transmitted in two manners, namely, SFBC and STBC, simultaneously,but because data transmission of an e-PDCCH needs to adopt twotransmitting diversity solutions, complexity of transmitting andreceiving on an eNB and a UE is increased. However, in this embodimentof the present invention, data can be transmitted only in need of onetransmitting diversity solution, so as to solve the problem of theincrease in the complexity of transmitting and receiving on the eNB andthe UE, and additionally, the time-frequency orthogonal reference signalalso improves the channel estimation performance.

The apparatus for transmitting data provided by the embodiments of thepresent invention can implement the method embodiments provided above.Reference may be made to the illustration in the method embodiments forthe specific function implementation, which is not described here again.The method and the apparatus for transmitting data provided by theembodiments of the present invention are applicable to the field ofcommunications systems, but are not merely limited thereto.

Persons of ordinary skill in the art should understand that, all or apart of processes in the method according to the embodiments may beaccomplished by relevant hardware under instructions of a computerprogram. The program may be stored in a computer-readable storagemedium. When the program is executed, the process of the methodaccording to the embodiments of the present invention is performed. Thestorage medium may be a magnetic disk, an optical disk, a read-onlymemory (Read-Only Memory, ROM), a random access memory (Random AccessMemory, RAM), and the like.

The foregoing descriptions are merely specific embodiments of thepresent invention, but are not intended to limit the protection scope ofthe present invention. Any variation or replacement readily figured outby persons skilled in the art within the technical scope disclosed inthe present invention shall all fall within the protection scope of thepresent invention. Therefore, the protection scope of the presentinvention is subject to the protection scope of the claims.

1. A method for receiving data, comprising: receiving data of two datastreams and reference signals, wherein at least two second resourcegroups are comprised in each first resource group of at least one firstresource group, wherein each of the second resource groups is capable ofbearing at least two reference signals, wherein the at least tworeference signals correspond to different antenna ports, wherein the twodata streams are mapped onto REs of two different antenna ports and thereference signals corresponding to the two different antenna ports areborne on two different second resource groups of the first resourcegroup; and decoding the received data streams, wherein the referencesignals comprise demodulation reference signals (DMRS).
 2. The method ofclaim 1, wherein time and frequency resources occupied by the twodifferent second resource groups are different from each other.
 3. Themethod of claim 1, wherein time and frequency resource occupied by thetwo different second resource groups are orthogonal to each other. 4.The method of claim 1, wherein the second resource group comprises 12resource elements (REs).
 5. The method of claim 1, wherein the firstresource group comprises two of the second resource groups.
 6. Themethod of claim 1, wherein the data is enhanced physical downlinkcontrol channel (E-PDCCH) data.
 7. The method of claim 1, wherein theREs corresponding to the antenna ports bearing the data streams compriseREs, in the first resource group, except an RE occupied by a physicaldownlink control channel (PDCCH) and a reference signal.
 8. The methodof claim 1, wherein the at least two reference signals borne on the sameone of the second resource groups occupy the same time frequencyresource and are distinguished by different sequences.
 9. The method ofclaim 1, wherein the received data streams are decoded with spacefrequency block coding or space time block coding.
 10. An apparatus forreceiving data, comprising: a receiver, configured to receive data oftwo data streams and reference signals, wherein at least two secondresource groups are comprised in each first resource group of at leastone first resource group, wherein each of the second resource groups iscapable of bearing at least two reference signals, wherein the at leasttwo reference signals correspond to different antenna ports, wherein thetwo data streams are mapped onto REs of two different antenna ports andthe reference signals corresponding to the two different antenna portsare borne on two different second resource groups of the first resourcegroup; and a decoder, configured to decode the received data streams,wherein the reference signals comprise demodulation reference signals(DMRS).
 11. The apparatus of claim 10, wherein time and frequencyresources occupied by the two different second resource groups areorthogonal to each other.
 12. The apparatus of claim 10, wherein timeand frequency resources occupied by the two different second resourcegroups are different from each other.
 13. The apparatus of claim 10,wherein the second resource group comprises 12 resource elements (REs).14. The apparatus of claim 10, wherein the first resource groupcomprises two of the second resource groups.
 15. The apparatus of claim10, wherein the data is enhanced physical downlink control channel(E-PDCCH) data.
 16. The apparatus of claim 10, wherein the REscorresponding to the antenna ports bearing the data streams compriseREs, in the first resource group, except an RE occupied by a physicaldownlink control channel (PDCCH) and a reference signal.
 17. Theapparatus of claim 10, wherein the at least two reference signals borneon the same one of the second resource groups occupy the same timefrequency resource and are distinguished by different sequences.
 18. Acomputer-readable storage medium storing computer readable codecomprising a program, that when executed by a processor disposed withina device, causes the device to perform the steps of: receiving data oftwo data streams and reference signals, wherein at least two secondresource groups are comprised in each first resource group of at leastone first resource group, wherein each of the second resource groups iscapable of bearing at least two reference signals, wherein the at leasttwo reference signals correspond to different antenna ports, wherein thetwo data streams are mapped onto REs of two different antenna ports andthe reference signals corresponding to the two different antenna portsare borne on two different second resource groups of the first resourcegroup; and decoding the received data streams, wherein the referencesignals comprise demodulation reference signals (DMRS).
 19. Thecomputer-readable storage medium of claim 18, wherein time and frequencyresources occupied by the two different second resource groups aredifferent from each other.
 20. The computer-readable storage medium ofclaim 18, wherein the REs corresponding to the antenna ports bearing thedata streams comprise REs, in the first resource group, except an REoccupied by a physical downlink control channel (PDCCH) and a referencesignal.
 21. The computer-readable storage medium of claim 18, whereinthe at least two reference signals borne on the same one of the secondresource groups occupy the same time frequency resource and aredistinguished by different sequences.